Yarn treating vat having guide wheel driven by a magnetic coupling



Jan. 30, 1951 J. K. WHlSNANT 2,539,982

YARN TREATING VAT HAVING GUIDE WHEEL DRIVEN BY A MAGNETIC COUPLING Filed Jn. 51, 1947 2 Sheets-Sheet l Jan. 30, 1951 J. K. WHISNANT YARN TREATING VAT HAVING GUIDE WHEEL DRIVEN BY A MAGNETIC COUPLING 2 Sheets-Sheet 2 Filed Jan. 31, 1947 4* pwlmlm Ltomw;

Patented Jan. 30, 1951 YARN TREATING VAT HAVING GUIDE WHEEL DRIVEN COUPLING BY A MAGNETIC John K. Whisnant, Enka, N. 0., assignor to American Enka Corporation, Enka, N. 0., a corporation of Delaware Application January 31, 1947, Serial No. 725,513

1 Claim.

This invention relates to thread guiding and propelling apparatus and is more particularly concerned with apparatus for advancing freshly formed rayon yarn through a treating bath.

In the two bath spinning of rayon which involves the extrusion of the yarn into an acid spin bath and the subsequent passage thereof under stretching conditions through a hot dilute acid bath, it has been customary to provide, in addition to draw-off devices for withdrawing the yarn from the spin bath and from the dilute acid bath, a small freely rotatable roller or a driven godet located in the second bath to guide the yarn therethrough. It has now proved expedient to use in this system, a large guiding wheel partially submerged in the dilute acid bath which serves to guide the yarn during its reversal of direction. The function of the guiding wheel and the wheel per se form no part of this invention as this is covered in a copending application Serial No. 650,608. In other treating phases of various rayon manufacturing processes, it may also be necessary or desirable to employ large guiding wheels which serve to control the passage of a thread or yarn through a liquid.

Theoretically these guide wheels may be driven by frictional contact with the thread passing around them or from a suitable mechanically connected external power source but, in practice neither of these expedients has been wholly satisfactory, particularly in handling freshly spun rayon yarn.

Since it is customary in the two bath spinning of rayon yarn to impart stretch to the thread by driving the godet which draws the thread from the dilute acid bath at a slightly greater 2 the foregoing difilcultles and to provide a positively driven guide wheel in which corrosion difliculties and nonuniform drag on the thread oryarn are wholly avoided.

It is proposed according to the present invention to provide a rotatable wheel which is magnetically driven through the wall of the bath tank by driving means which are wholly protected by the wall of the bath tank from the corrosive effects of the bath tank contents.

Other objects and advantages of this invention will be apparent upon consideration of the following detailed description of a preferred embodiment thereof in coniunction with the annexed drawings wherein:

Figure 1 is a. schematic perspective view a single unit of a two bath spinning system illustrating the position of the driving wheel of the present invention in the assembly;

Figure 2 is a vertical sectional view of the guide wheel of the present invention in association with a portion of the apparatus of Figure l: I Figure 3 is a view in elevation taken along the line 3-3 of Figure 2; and

Figure 4 is view in elevation taken along the line H of Figure 2.

Referring now with greater particularity to Figure l, the numeral Iii represents a tank conperipheral speed than the godet which draws the yarn from the spin bath, it is apparent that, if the frictional drag imposed on the yarn by the guide wheel is non-uniform, stretch variations will occur which deleteriously effect the quality of the finished thread. It has been found that it is not entirely practical from a commercial point of view to provide a thread-driven wheel which will afford a frictional drag on the thread which is sufllciently uniform to meet operating requirements. Attempts to'overcome the difficulty by providing an external driving means for the guide wheel have not met with success due to the fact that passage of the driving shaft through the wall of the tank which contains the dilute acid presents serious packing difficulties in that the acid tends to corrode the shaft and to interfere with its proper operation.

taining a conventional acid spin bath. The spinning solution such as viscose is led to the tank It through a pipe II from a source not shown and is extruded through a spinnerette [2 located within the tank Ill and below the surface of the acid spin bath. Freshly spun yarn is drawn from the spinnerette by a godet I! supported from a panel [4 and driven by conventional means, not shown. From the godet It the yarn is passed downwardly and into a tank i5 containing hot dilute acid. In its passage through the tank It it is guided and propelled by a large guiding wheel l6 partially submerged in the hot dilute acid. After leaving the guide wheel IS the thread is drawn upwardly by a godet i'l similar in structure and operation to the godet l3, and from the godet II the thread is passed to a point of collection or to after treatment, a point of collection being diagrammatically indicated at it. It is noted that the tanks l0 and ii are of approximately equivalent dimensions and are separated by a hollow partition i9, trapezoidal in section.-

Within the partition is there is located a driving shaft ill driven at an appropriate speed by conventional means, not shown, and this drive shaft is provided with gear 2! which meshes with It is an object of this invention to overcome 66 a gear 22 mounted on a stub shaft 23 for rotation therewith. suitable conventional bearing means 24 and 26 are provided to guide and support the shaft 23. The end of the shaft 23 adjacent the tank It is provided with a driving part 26 of a magnetic coupling. This part consists of a generally rectangular piece of metal provided with pole pieces 21 and 23 adapted to lie'closely adjacent a partition wall 29 separating the tank 46 from the hollow working space within the partition i9. The wall 29 is constructed of any material that is substantially non-magnetic, such as lead or plastic. It is understood that the driving member 26 will be either permanently magnetized or an electro-magnet of conventional design, the opposite pole pieces being designated by reference characters 21 and 23.

Mounted on the wall 29 and lying within the tank ii there is a stub shaft 30. This shaft is supported from one end only by suitable attachment to the wall 29 and extends in alignment with the shaft '23. The shaft 30 may be made of suitable material which is resistant to the acid contained within the tank l and it serves to support for rotation thereon the guide wheel l6. The guide wheel includes a peripheral yarn contacting surface 3|, a flange 32 and a hub 33. The hub surrounds the shaft and rotates thereon. The flange 32 acts to prevent the yarn from getting between the partition wall 29 and the wheel proper, while the annular surface 3| acts as the supporting and propelling surface for the yarn. Countersunk within the wheel Hi, there is a diametrically disposed bar 34 of magnetic material which is fixed to the bath wheel and which lies adjacent the driving member 26 but on the other side of the partition 29 therefrom. If desirable, several of such bars may be employed, provided of course, the driving member contains the same number of poles. The magnetic material 34 may be either magnetized or unmagnetized material of high permeability. To increase the strength of the couple between the driving element 26 and the magnet 34, it is desirable, of course, to have the members 26 and 34 both permanently magnetized and with their pole pieces arranged as is indicated in Figure 2.

It can now be seen that the Wheel l6 lies wholly within the bath tank l5 and there is no shaft or other connection which passes through the partition. Accordingly, the packing difiiculties and protective measures against corrosion which were of considerable concern in the prior art, are wholly obviated. Due to the fact that the magnetic coupling is established between the pole pieces 21 and 28 and the corresponding pole pieces of the magnet 34, the guide wheel is is positively driven and variations in the frictional drag between the bath wheel and its bearings are absorbed by the driving mechanism rather than by the yarn so that protection of the yarn against uncontrolled stretch is afforded. It is of course, understood that the driving memberv might be unmagnetized thereby constituting a pole piece for a permanently magnetized bar located on the wheel.

While the present invention has been described with reference to an embodiment thereof in a two bath stretch spinnin system, it is apparent that the invent-ion is of broad utility in various instal- 4 lations where it is necessary to drive a wheel wholly or partially immersed in a fluid, the escape the machine, one to serve each spinning position.

The above described type of magnetic drive has the additional advantage of providing synchronous rotation of the driving member and the driven member, because as soon as the magnetic field is broken, the torque created on the driven member drops to substantially zero.

What is claimed is:

Apparatus for guiding and propelling a freshly formed rayon yarn through an acid treating bath that comprises a tank for holding an acid treating bath having an inclined wall of, non-magnetic material, a stub shaft of acid resistant material, a support having an axial bearing surface for mounting said stub shaft on the inside of said inclined wall and normal thereto, a wheel having a hub surrounding said stub shaft, a face of said wheel paralleling said inclined wall and resting against said bearing surface, said wheel hav-= ing a peripheral yarn contacting surface adapted for guiding and propelling a freshly formed rayon yarn through said acid treating bath, said'wheel also having a flange located on said peripheral surface adjacent said inclined wall and adapted to prevent yarn carried by said peripheral sur-'- face from slipping between said face and said inclined wall, a bar of magnetizable high per-'- meability material diametrically counter-sunk in said face of said wheel, a, driving shaft extending in alignment with said stub shaft outside of said inclined wall, a U-shaped permanent magnet mounted on the end of said driving shaft ad'- jacent said inclined wall, and means for driving I said permanent magnet and said driving shaft.-

JOHN K. WHISNANT;

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 644,498 Cook Feb. 27, 1900 778,236 Fries Dec. 27, 1904 1,259,526 Knibiehler Mar. 19, 1 918 1,722,813 McGann July30, 1929 1,847,006 Kalischer Feb. 23, 1932 1,900,811 Hegan et a1; Mar. 7, 1933 2,056,177 Erbguth Oct. 6, 1936 2,145,019 Backup Jan. 24, 1939 2,346,696 Montz et al. Apr. 18, 1944 2,348,415 Polak May 9, 1944 2,366,562 Schug Jan. 2, 1945 2,369,190 Thurmond Feb. 13, 1945 FOREIGN PATENTS Number Country Date 179,295 Great Britain May 2, 1922 

